iPhone hacked

Ok, so I was talking to someone on Instagram and after a few days They asked me to download hang outs, it’s an app. And without thinking I downloaded it and was talking to him on their and after a few days it crashed on me and I didn’t know it at the time but he hacked my phone on Jan 14th and I found out the 16-17th of Jan. And so ever since that I Change my Apple ID And email passwords I got a new phone and that one was an android I was using a new email like I was afraid to use my iPhone completely and then I realized that he had hacked into my other email on my new android phone because when I tried updating information, like the bank, My kids school etc. Xfinity ,my health chart, Like all of those places I was trying to update them with my new information and he kept updating it with different information so that’s how I found out that he changed my password to my newest email because they had recommended that I change my email again and I couldn’t get in my new email on my new phone so I went back to using my iPhone because I had no idea how this person had gotten into the new phone and was changing things again I still cannot access my Facebook account or my Instagram or my messenger for Facebook.This person did not log me out of my Apple ID so I was able to get in my phone to change passwords but like I said he kept on trying to update everybody that I was updating so which then led me to believe that he was still in my phone watching what I was doing. And I have no idea what jail house is can you explain that to me please

Also, when I purchased my new phone after the hacking , I also bought my children two new phones and I put a two step verification on her phone and someone took it off. And her phone will sometimes act as if someone else is controlling it. I will experience screenshots on my phone and my phone will be on my dresser, and there is no way possible that I took a screenshot on my phone. It will say screenshot saved and then it won’t be anywhere in my photos. It’s so weird

How do you know that forsure though? How did someone change my Apple ID then?

What does jailbroke mean?